/******************************************************************************
   *
   * Module Name: exresolv - AML Interpreter object resolution
   *
   *****************************************************************************/
  
  /*
   * Copyright (C) 2000 - 2013, Intel Corp.
   * All rights reserved.
   *
   * Redistribution and use in source and binary forms, with or without
   * modification, are permitted provided that the following conditions
   * are met:
   * 1. Redistributions of source code must retain the above copyright
   *    notice, this list of conditions, and the following disclaimer,
   *    without modification.
   * 2. Redistributions in binary form must reproduce at minimum a disclaimer
   *    substantially similar to the "NO WARRANTY" disclaimer below
   *    ("Disclaimer") and any redistribution must be conditioned upon
   *    including a substantially similar Disclaimer requirement for further
   *    binary redistribution.
   * 3. Neither the names of the above-listed copyright holders nor the names
   *    of any contributors may be used to endorse or promote products derived
   *    from this software without specific prior written permission.
   *
   * Alternatively, this software may be distributed under the terms of the
   * GNU General Public License ("GPL") version 2 as published by the Free
   * Software Foundation.
   *
   * NO WARRANTY
   * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
   * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
   * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTIBILITY AND FITNESS FOR
   * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
   * HOLDERS OR CONTRIBUTORS BE LIABLE FOR SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
   * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
   * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
   * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
   * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING
   * IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
   * POSSIBILITY OF SUCH DAMAGES.
   */
  
  #include <acpi/acpi.h>
  #include "accommon.h"
  #include "amlcode.h"
  #include "acdispat.h"
  #include "acinterp.h"
  #include "acnamesp.h"
  
  #define _COMPONENT          ACPI_EXECUTER
  ACPI_MODULE_NAME("exresolv")
  
  /* Local prototypes */
  static acpi_status
  acpi_ex_resolve_object_to_value(union acpi_operand_object **stack_ptr,
  				struct acpi_walk_state *walk_state);
  
  /*******************************************************************************
   *
   * FUNCTION:    acpi_ex_resolve_to_value
   *
   * PARAMETERS:  **stack_ptr         - Points to entry on obj_stack, which can
   *                                    be either an (union acpi_operand_object *)
   *                                    or an acpi_handle.
   *              walk_state          - Current method state
   *
   * RETURN:      Status
   *
   * DESCRIPTION: Convert Reference objects to values
   *
   ******************************************************************************/
  
  acpi_status
  acpi_ex_resolve_to_value(union acpi_operand_object **stack_ptr,
  			 struct acpi_walk_state *walk_state)
  {
  	acpi_status status;
  
  	ACPI_FUNCTION_TRACE_PTR(ex_resolve_to_value, stack_ptr);
  
  	if (!stack_ptr || !*stack_ptr) {
  		ACPI_ERROR((AE_INFO, "Internal - null pointer"));
  		return_ACPI_STATUS(AE_AML_NO_OPERAND);
  	}
  
  	/*
  	 * The entity pointed to by the stack_ptr can be either
  	 * 1) A valid union acpi_operand_object, or
  	 * 2) A struct acpi_namespace_node (named_obj)
  	 */
  	if (ACPI_GET_DESCRIPTOR_TYPE(*stack_ptr) == ACPI_DESC_TYPE_OPERAND) {
  		status = acpi_ex_resolve_object_to_value(stack_ptr, walk_state);
  		if (ACPI_FAILURE(status)) {
  			return_ACPI_STATUS(status);
  		}
  
  		if (!*stack_ptr) {
  			ACPI_ERROR((AE_INFO, "Internal - null pointer"));
  			return_ACPI_STATUS(AE_AML_NO_OPERAND);
  		}
  	}
  
  	/*
  	 * Object on the stack may have changed if acpi_ex_resolve_object_to_value()
  	 * was called (i.e., we can't use an _else_ here.)
  	 */
  	if (ACPI_GET_DESCRIPTOR_TYPE(*stack_ptr) == ACPI_DESC_TYPE_NAMED) {
  		status =
  		    acpi_ex_resolve_node_to_value(ACPI_CAST_INDIRECT_PTR
  						  (struct acpi_namespace_node,
  						   stack_ptr), walk_state);
  		if (ACPI_FAILURE(status)) {
  			return_ACPI_STATUS(status);
  		}
  	}
  
  	ACPI_DEBUG_PRINT((ACPI_DB_EXEC, "Resolved object %p
  ", *stack_ptr));
  	return_ACPI_STATUS(AE_OK);
  }
  
  /*******************************************************************************
   *
   * FUNCTION:    acpi_ex_resolve_object_to_value
   *
   * PARAMETERS:  stack_ptr       - Pointer to an internal object
   *              walk_state      - Current method state
   *
   * RETURN:      Status
   *
   * DESCRIPTION: Retrieve the value from an internal object. The Reference type
   *              uses the associated AML opcode to determine the value.
   *
   ******************************************************************************/
  
  static acpi_status
  acpi_ex_resolve_object_to_value(union acpi_operand_object **stack_ptr,
  				struct acpi_walk_state *walk_state)
  {
  	acpi_status status = AE_OK;
  	union acpi_operand_object *stack_desc;
  	union acpi_operand_object *obj_desc = NULL;
  	u8 ref_type;
  
  	ACPI_FUNCTION_TRACE(ex_resolve_object_to_value);
  
  	stack_desc = *stack_ptr;
  
  	/* This is an object of type union acpi_operand_object */
  
  	switch (stack_desc->common.type) {
  	case ACPI_TYPE_LOCAL_REFERENCE:
  
  		ref_type = stack_desc->reference.class;
  
  		switch (ref_type) {
  		case ACPI_REFCLASS_LOCAL:
  		case ACPI_REFCLASS_ARG:
  			/*
  			 * Get the local from the method's state info
  			 * Note: this increments the local's object reference count
  			 */
  			status = acpi_ds_method_data_get_value(ref_type,
  							       stack_desc->
  							       reference.value,
  							       walk_state,
  							       &obj_desc);
  			if (ACPI_FAILURE(status)) {
  				return_ACPI_STATUS(status);
  			}
  
  			ACPI_DEBUG_PRINT((ACPI_DB_EXEC,
  					  "[Arg/Local %X] ValueObj is %p
  ",
  					  stack_desc->reference.value,
  					  obj_desc));
  
  			/*
  			 * Now we can delete the original Reference Object and
  			 * replace it with the resolved value
  			 */
  			acpi_ut_remove_reference(stack_desc);
  			*stack_ptr = obj_desc;
  			break;
  
  		case ACPI_REFCLASS_INDEX:
  
  			switch (stack_desc->reference.target_type) {
  			case ACPI_TYPE_BUFFER_FIELD:
  
  				/* Just return - do not dereference */
  				break;
  
  			case ACPI_TYPE_PACKAGE:
  
  				/* If method call or copy_object - do not dereference */
  
  				if ((walk_state->opcode ==
  				     AML_INT_METHODCALL_OP)
  				    || (walk_state->opcode == AML_COPY_OP)) {
  					break;
  				}
  
  				/* Otherwise, dereference the package_index to a package element */
  
  				obj_desc = *stack_desc->reference.where;
  				if (obj_desc) {
  					/*
  					 * Valid object descriptor, copy pointer to return value
  					 * (i.e., dereference the package index)
  					 * Delete the ref object, increment the returned object
  					 */
  					acpi_ut_remove_reference(stack_desc);
  					acpi_ut_add_reference(obj_desc);
  					*stack_ptr = obj_desc;
  				} else {
  					/*
  					 * A NULL object descriptor means an uninitialized element of
  					 * the package, can't dereference it
  					 */
  					ACPI_ERROR((AE_INFO,
  						    "Attempt to dereference an Index to NULL package element Idx=%p",
  						    stack_desc));
  					status = AE_AML_UNINITIALIZED_ELEMENT;
  				}
  				break;
  
  			default:
  
  				/* Invalid reference object */
  
  				ACPI_ERROR((AE_INFO,
  					    "Unknown TargetType 0x%X in Index/Reference object %p",
  					    stack_desc->reference.target_type,
  					    stack_desc));
  				status = AE_AML_INTERNAL;
  				break;
  			}
  			break;
  
  		case ACPI_REFCLASS_REFOF:
  		case ACPI_REFCLASS_DEBUG:
  		case ACPI_REFCLASS_TABLE:
  
  			/* Just leave the object as-is, do not dereference */
  
  			break;
  
  		case ACPI_REFCLASS_NAME:	/* Reference to a named object */
  
  			/* Dereference the name */
  
  			if ((stack_desc->reference.node->type ==
  			     ACPI_TYPE_DEVICE)
  			    || (stack_desc->reference.node->type ==
  				ACPI_TYPE_THERMAL)) {
  
  				/* These node types do not have 'real' subobjects */
  
  				*stack_ptr = (void *)stack_desc->reference.node;
  			} else {
  				/* Get the object pointed to by the namespace node */
  
  				*stack_ptr =
  				    (stack_desc->reference.node)->object;
  				acpi_ut_add_reference(*stack_ptr);
  			}
  
  			acpi_ut_remove_reference(stack_desc);
  			break;
  
  		default:
  
  			ACPI_ERROR((AE_INFO,
  				    "Unknown Reference type 0x%X in %p",
  				    ref_type, stack_desc));
  			status = AE_AML_INTERNAL;
  			break;
  		}
  		break;
  
  	case ACPI_TYPE_BUFFER:
  
  		status = acpi_ds_get_buffer_arguments(stack_desc);
  		break;
  
  	case ACPI_TYPE_PACKAGE:
  
  		status = acpi_ds_get_package_arguments(stack_desc);
  		break;
  
  	case ACPI_TYPE_BUFFER_FIELD:
  	case ACPI_TYPE_LOCAL_REGION_FIELD:
  	case ACPI_TYPE_LOCAL_BANK_FIELD:
  	case ACPI_TYPE_LOCAL_INDEX_FIELD:
  
  		ACPI_DEBUG_PRINT((ACPI_DB_EXEC,
  				  "FieldRead SourceDesc=%p Type=%X
  ",
  				  stack_desc, stack_desc->common.type));
  
  		status =
  		    acpi_ex_read_data_from_field(walk_state, stack_desc,
  						 &obj_desc);
  
  		/* Remove a reference to the original operand, then override */
  
  		acpi_ut_remove_reference(*stack_ptr);
  		*stack_ptr = (void *)obj_desc;
  		break;
  
  	default:
  
  		break;
  	}
  
  	return_ACPI_STATUS(status);
  }
  
  /*******************************************************************************
   *
   * FUNCTION:    acpi_ex_resolve_multiple
   *
   * PARAMETERS:  walk_state          - Current state (contains AML opcode)
   *              operand             - Starting point for resolution
   *              return_type         - Where the object type is returned
   *              return_desc         - Where the resolved object is returned
   *
   * RETURN:      Status
   *
   * DESCRIPTION: Return the base object and type. Traverse a reference list if
   *              necessary to get to the base object.
   *
   ******************************************************************************/
  
  acpi_status
  acpi_ex_resolve_multiple(struct acpi_walk_state *walk_state,
  			 union acpi_operand_object *operand,
  			 acpi_object_type * return_type,
  			 union acpi_operand_object **return_desc)
  {
  	union acpi_operand_object *obj_desc = (void *)operand;
  	struct acpi_namespace_node *node;
  	acpi_object_type type;
  	acpi_status status;
  
  	ACPI_FUNCTION_TRACE(acpi_ex_resolve_multiple);
  
  	/* Operand can be either a namespace node or an operand descriptor */
  
  	switch (ACPI_GET_DESCRIPTOR_TYPE(obj_desc)) {
  	case ACPI_DESC_TYPE_OPERAND:
  
  		type = obj_desc->common.type;
  		break;
  
  	case ACPI_DESC_TYPE_NAMED:
  
  		type = ((struct acpi_namespace_node *)obj_desc)->type;
  		obj_desc =
  		    acpi_ns_get_attached_object((struct acpi_namespace_node *)
  						obj_desc);
  
  		/* If we had an Alias node, use the attached object for type info */
  
  		if (type == ACPI_TYPE_LOCAL_ALIAS) {
  			type = ((struct acpi_namespace_node *)obj_desc)->type;
  			obj_desc =
  			    acpi_ns_get_attached_object((struct
  							 acpi_namespace_node *)
  							obj_desc);
  		}
  		break;
  
  	default:
  		return_ACPI_STATUS(AE_AML_OPERAND_TYPE);
  	}
  
  	/* If type is anything other than a reference, we are done */
  
  	if (type != ACPI_TYPE_LOCAL_REFERENCE) {
  		goto exit;
  	}
  
  	/*
  	 * For reference objects created via the ref_of, Index, or Load/load_table
  	 * operators, we need to get to the base object (as per the ACPI
  	 * specification of the object_type and size_of operators). This means
  	 * traversing the list of possibly many nested references.
  	 */
  	while (obj_desc->common.type == ACPI_TYPE_LOCAL_REFERENCE) {
  		switch (obj_desc->reference.class) {
  		case ACPI_REFCLASS_REFOF:
  		case ACPI_REFCLASS_NAME:
  
  			/* Dereference the reference pointer */
  
  			if (obj_desc->reference.class == ACPI_REFCLASS_REFOF) {
  				node = obj_desc->reference.object;
  			} else {	/* AML_INT_NAMEPATH_OP */
  
  				node = obj_desc->reference.node;
  			}
  
  			/* All "References" point to a NS node */
  
  			if (ACPI_GET_DESCRIPTOR_TYPE(node) !=
  			    ACPI_DESC_TYPE_NAMED) {
  				ACPI_ERROR((AE_INFO,
  					    "Not a namespace node %p [%s]",
  					    node,
  					    acpi_ut_get_descriptor_name(node)));
  				return_ACPI_STATUS(AE_AML_INTERNAL);
  			}
  
  			/* Get the attached object */
  
  			obj_desc = acpi_ns_get_attached_object(node);
  			if (!obj_desc) {
  
  				/* No object, use the NS node type */
  
  				type = acpi_ns_get_type(node);
  				goto exit;
  			}
  
  			/* Check for circular references */
  
  			if (obj_desc == operand) {
  				return_ACPI_STATUS(AE_AML_CIRCULAR_REFERENCE);
  			}
  			break;
  
  		case ACPI_REFCLASS_INDEX:
  
  			/* Get the type of this reference (index into another object) */
  
  			type = obj_desc->reference.target_type;
  			if (type != ACPI_TYPE_PACKAGE) {
  				goto exit;
  			}
  
  			/*
  			 * The main object is a package, we want to get the type
  			 * of the individual package element that is referenced by
  			 * the index.
  			 *
  			 * This could of course in turn be another reference object.
  			 */
  			obj_desc = *(obj_desc->reference.where);
  			if (!obj_desc) {
  
  				/* NULL package elements are allowed */
  
  				type = 0;	/* Uninitialized */
  				goto exit;
  			}
  			break;
  
  		case ACPI_REFCLASS_TABLE:
  
  			type = ACPI_TYPE_DDB_HANDLE;
  			goto exit;
  
  		case ACPI_REFCLASS_LOCAL:
  		case ACPI_REFCLASS_ARG:
  
  			if (return_desc) {
  				status =
  				    acpi_ds_method_data_get_value(obj_desc->
  								  reference.
  								  class,
  								  obj_desc->
  								  reference.
  								  value,
  								  walk_state,
  								  &obj_desc);
  				if (ACPI_FAILURE(status)) {
  					return_ACPI_STATUS(status);
  				}
  				acpi_ut_remove_reference(obj_desc);
  			} else {
  				status =
  				    acpi_ds_method_data_get_node(obj_desc->
  								 reference.
  								 class,
  								 obj_desc->
  								 reference.
  								 value,
  								 walk_state,
  								 &node);
  				if (ACPI_FAILURE(status)) {
  					return_ACPI_STATUS(status);
  				}
  
  				obj_desc = acpi_ns_get_attached_object(node);
  				if (!obj_desc) {
  					type = ACPI_TYPE_ANY;
  					goto exit;
  				}
  			}
  			break;
  
  		case ACPI_REFCLASS_DEBUG:
  
  			/* The Debug Object is of type "DebugObject" */
  
  			type = ACPI_TYPE_DEBUG_OBJECT;
  			goto exit;
  
  		default:
  
  			ACPI_ERROR((AE_INFO,
  				    "Unknown Reference Class 0x%2.2X",
  				    obj_desc->reference.class));
  			return_ACPI_STATUS(AE_AML_INTERNAL);
  		}
  	}
  
  	/*
  	 * Now we are guaranteed to have an object that has not been created
  	 * via the ref_of or Index operators.
  	 */
  	type = obj_desc->common.type;
  
  exit:
  	/* Convert internal types to external types */
  
  	switch (type) {
  	case ACPI_TYPE_LOCAL_REGION_FIELD:
  	case ACPI_TYPE_LOCAL_BANK_FIELD:
  	case ACPI_TYPE_LOCAL_INDEX_FIELD:
  
  		type = ACPI_TYPE_FIELD_UNIT;
  		break;
  
  	case ACPI_TYPE_LOCAL_SCOPE:
  
  		/* Per ACPI Specification, Scope is untyped */
  
  		type = ACPI_TYPE_ANY;
  		break;
  
  	default:
  
  		/* No change to Type required */
  
  		break;
  	}
  
  	*return_type = type;
  	if (return_desc) {
  		*return_desc = obj_desc;
  	}
  	return_ACPI_STATUS(AE_OK);
  }